Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.watres.2011.07.010
Title (Primary) Remediation of groundwater contaminated with MTBE and benzene: the potential of vertical-flow soil filter systems
Author van Afferden, M.; Rahman, K.Z.; Mosig, P.; De Biase, C.; Thullner, M.; Oswalt, P.; Müller, R.A.
Source Titel Water Research
Year 2011
Department UMB; GWS; UBZ
Volume 45
Issue 16
Page From 5063
Page To 5074
Language englisch
Keywords Benzene; Groundwater remediation; Hydraulic loading rate; MTBE; Pilot-scale constructed wetland; Vertical-flow soil filter; Willow tree

Field investigations on the treatment of MTBE and benzene from contaminated groundwater in pilot or full-scale constructed wetlands are lacking hugely. The aim of this study was to develop a biological treatment technology that can be operated in an economic, reliable and robust mode over a long period of time. Two pilot-scale vertical-flow soil filter eco-technologies, a roughing filter (RF) and a polishing filter (PF) with plants (willows), were operated independently in a single-stage configuration and coupled together in a multi-stage (RF + PF) configuration to investigate the MTBE and benzene removal performances. Both filters were loaded with groundwater from a refinery site contaminated with MTBE and benzene as the main contaminants, with a mean concentration of 2970 ± 816 and 13,966 ± 1998 μg L−1, respectively. Four different hydraulic loading rates (HLRs) with a stepwise increment of 60, 120, 240 and 480 L m−2 d−1 were applied over a period of 388 days in the single-stage operation. At the highest HLR of 480 L m−2 d−1, the mean concentrations of MTBE and benzene were found to be 550 ± 133 and 65 ± 123 μg L−1 in the effluent of the RF. In the effluent of the PF system, respective mean MTBE and benzene concentrations of 49 ± 77 and 0.5 ± 0.2 μg L−1 were obtained, which were well below the relevant MTBE and benzene limit values of 200 and 1 μg L−1 for drinking water quality. But a dynamic fluctuation in the effluent MTBE concentration showed a lack of stability in regards to the increase in the measured values by nearly 10%, which were higher than the limit value. Therefore, both (RF + PF) filters were combined in a multi-stage configuration and the combined system proved to be more stable and effective with a highly efficient reduction of the MTBE and benzene concentrations in the effluent. Nearly 70% of MTBE and 98% of benzene were eliminated from the influent groundwater by the first vertical filter (RF) and the remaining amount was almost completely diminished (∼100% reduction) after passing through the second filter (PF), with a mean MTBE and benzene concentration of 5 ± 10 and 0.6 ± 0.2 μg L−1 in the final effluent. The emission rate of volatile organic compounds mass into the air from the systems was less than 1% of the inflow mass loading rate. The results obtained in this study not only demonstrate the feasibility of vertical-flow soil filter systems for treating groundwater contaminated with MTBE and benzene, but can also be considered a major step forward towards their application under full-scale conditions for commercial purposes in the oil and gas industries.
Persistent UFZ Identifier
van Afferden, M., Rahman, K.Z., Mosig, P., De Biase, C., Thullner, M., Oswalt, P., Müller, R.A. (2011):
Remediation of groundwater contaminated with MTBE and benzene: the potential of vertical-flow soil filter systems
Water Res. 45 (16), 5063 - 5074 10.1016/j.watres.2011.07.010